PORT ST. LUCIE – Pedro Martinez’s right shoulder didn’t have any huge telling scars when he showed it to reporters yesterday. Not only is there nothing too noticeable, but Martinez was far from downcast in assessing his health.

Opening his third Mets camp at Tradition Field, Martinez reported here yesterday. The 35-year-old was upbeat and in good spirits, telling reporters he believes he’ll be back when expected – the second half of the season – and thinks offseason shoulder surgery could help make his future with the Mets superior to his past.

Martinez worked out using a program he says takes 3½ hours and, odds are, will increase in duration over the next few days. There is one glaring difference in this camp for Martinez: He said there is no possibility of even picking up a ball until next month, much less pitching.

“It’s going to be different because I want to be part of whatever they go through,” Martinez said, adding, “they’ll probably leave and I will not be able to get on the mound.”

For now, what Martinez can do is exercises. “A little bit of everything,” he said, laughing.

He reported to camp weighing 193 pounds, which he says is his highest total since 2002, when he was 20-4 with a 2.26 ERA. Last year he was 188-190 pounds.

Martinez said he thinks that a return around the All-Star break is possible. Martinez said he “was ahead of schedule two weeks after the surgery,” but will base his pitching timetable on medical advice.

“I feel pretty confident, the way I feel right now, that I could be back [in July], but one thing, the doctors are the ones that know,” he said. “And if they tell me you’re going to pitch in September, that’s when I’m going to pitch. If they tell me you’re going to pitch in July, that you look good enough to pitch in July, then I’ll pitch in July. I would love to pitch right now, but I’m not going to go against them. I’ve been stubborn enough to hurt myself, so imagine how much I want to pitch.”

Martinez does have to temper his excitement. He admits last year he was too aggressive. He said he thinks he “should have stopped on time,” preventing himself from both suffering a torn muscle tendon of his left calf and his shoulder.

His brother, former pitcher Ramon Martinez, and former major league starter Jose Rijo told Martinez, “take your time” with his rehab.

“[Ramon] was able to pitch when he got back,” Pedro said, “but he never felt the same because he didn’t take his time.”

When the time arrives that Pedro does come back, he said there’s a good chance he’ll be at his best as a Met – “probably [better] than people have seen at Shea.”

He’s been told by doctors that he can expect to be “stronger and throwing harder” than he has in his two seasons with the Mets.

Last spring, Martinez had to deal with an ailing right big toe, and during the season he dealt with an inflamed right hip and his calf problems. This year, Martinez said he has been “running in the sand, full gas, with a parachute behind my back.